Activity, Respiration, and Excretion of Ammonia by Atlantic Salmon (Salmo salar) Smolt and Postsmolt

1989 ◽  
Vol 46 (5) ◽  
pp. 790-795 ◽  
Author(s):  
A. J. Wiggs ◽  
E. B. Henderson ◽  
R. L. Saunders ◽  
M. N. Kutty
Keyword(s):  
Oxygen Consumption ◽  
Atlantic Salmon ◽  
Spontaneous Activity ◽  
Salmo Salar ◽  
Condition Factor ◽  
Ammonia Excretion ◽  
Initial Increase ◽  
Atlantic Salmon Salmo Salar ◽  
Substantial Change ◽  
Increased Activity

Spontaneous activity, oxygen consumption, and excretion of ammonia by juvenile Atlantic salmon (Salmo salar) were measured over 17 wk as the appearance of the fish changed from early smolt to smolt and then postsmolt. A substantial change in routine oxygen consumption from 66 to 148 mL∙kg−1∙h−1 was primarily correlated with the increase in activity. An initial increase in ammonia excretion from about 5 to about 14 mL∙kg−1∙h−1 was largely correlated with the decline in condition factor from 0.99 to 0.79 suggesting that increased metabolic needs caused by the increased activity were not being met by the amount of food ingested. This is supported by the secondary increase in condition factor (C.F. = 0.93) and decrease in ammonia excretion (to about 7 mg∙kg−1∙h−1) that occurred after the meal size was increased.

Hourly and total oxygen consumption by ova of Atlantic salmon, Salmo salar L., during embryogenesis, at two temperatures and three levels of dissolved oxygen

1979 ◽  
Vol 57 (6) ◽  
pp. 1196-1200 ◽  
Author(s):  
T. Hamor ◽  
E. T. Garside
Keyword(s):  
Oxygen Consumption ◽  
Atlantic Salmon ◽  
Oxygen Uptake ◽  
Dissolved Oxygen ◽  
Salmo Salar ◽  
Developmental Time ◽  
Total Oxygen ◽  
Weighted Mean ◽  
Atlantic Salmon Salmo Salar ◽  
Two Temperatures

Weighted mean hourly rates of oxygen consumption in embryonated ova of Atlantic salmon, Salmo salar L., during embryogenesis, were reduced significantly by levels of dissolved oxygen below air saturation and by a temperature of 5 °C, relative to those for ova incubated at 10 °C. Total oxygen consumption during embryogenesis also was reduced significantly by the lower levels of dissolved oxygen, but not by temperature. The decrease in the pace of embryogenesis in the lots of ova at 5 °C extended the developmental time so that the lower rate of oxygen uptake was offset. Thus, within each level of dissolved oxygen there was no appreciable difference in the products of time units and units of oxygen uptake. At 5 °C, 100% air saturation, mean hourly uptake was 0.0141 mg O2/ovum, and total uptake was 28.153 mg O2/ovum. At 10 °C, 100% air saturation, these values were 0.0270 mg O2/ovum, and 27.974 mg O2/ovum, respectively. Values for ova incubated at 50 and 30% air saturation were correspondingly lower.

Winter temperature and food quality affect age at maturity: an experimental test with Atlantic salmon (Salmo salar)

2012 ◽  
Vol 69 (11) ◽  
pp. 1817-1826 ◽  
Author(s):  
Bror Jonsson ◽  
Anders G. Finstad ◽  
Nina Jonsson
Keyword(s):  
Growth Rate ◽  
Atlantic Salmon ◽  
Direct Effect ◽  
Salmo Salar ◽  
Food Quality ◽  
Condition Factor ◽  
Sea Water ◽  
Winter Temperature ◽  
Age At Maturity ◽  
Atlantic Salmon Salmo Salar

Field studies have revealed that many ectotherms mature younger and smaller in warmer environments although they grow faster. This has puzzled ecologists because the direct effect of factors that accelerate growth is expected to be larger, not smaller size. We tested this experimentally for Atlantic salmon (Salmo salar) at two winter temperatures and diets. Logistic regression revealed that the probability of maturation during the second year in sea water, relative to the probability of older maturation, increased with temperature and growth rate during the first winter. Also, large size and high condition factor 1 year prior to maturation stimulated maturation. In females, a high lipid diet increased the probability of maturation as one-sea-winter fish, and there were significant interactions between winter temperature and food quality and between body size and condition factor the first autumn in sea water. Thus, if the direct effect of temperature on growth rate is the main effect of warming, salmon are likely to attain maturity younger and smaller. Also, richer food decreased age at maturation in females. This finding has consequences for interpretations of climate change impacts on age at maturity in Atlantic salmon and may also hold for many other ectotherm species.

Effect of 6-, 12-, and 18-month Photoperiod Cycles on Smolting and Sexual Maturation in Juvenile Atlantic Salmon (Salmo salar)

1992 ◽  
Vol 49 (11) ◽  
pp. 2273-2280 ◽  
Author(s):  
J. Duston ◽  
R. L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sexual Maturation ◽  
Condition Factor ◽  
Temperature Cycle ◽  
Frequency Distributions ◽  
Atlantic Salmon Salmo Salar ◽  
Sexually Mature ◽  
Mature Male Parr ◽  
Modal Group

The results support the hypothesis that the commencement of smolting can occur during the decreasing phase of the annual photoperiod cycle, and sexual maturation during the increasing phase of the cycle, provided individuals have attained certain (unknown) growth thresholds. Thereafter the completion of smolting is entrained by the increasing phase of the photoperiod cycle, and sexual maturation by the decreasing phase. Three groups of Atlantic salmon (Salmo salar) were raised in freshwater for over 2 yr from the eyed egg stage under photoperiod cycles of either 6-, 12- (control), or 18-mo periodicity and an ambient 12-mo temperature cycle. Smolting was judged by changes in salinity tolerance and condition factor. All groups developed bimodal length–frequency distributions by December following hatch. Fish continued to be recruited into the upper modal group (UMG) beyond the shortest day of the photoperiod cycle, providing temperature was not limiting growth. The 6-, 12-, and 18-mo photoperiod cycles resulted in approximately 50, 60, and 100% of the populations being recruited into the UMG. Sexually mature male parr (1 + yr old) occurred only in the lower modal group of the 6- and 12-mo groups.

Contrasts in development and smolting of genetically distinct sympatric anadromous and nonanadromous Atlantic salmon, Salmo salar

1991 ◽  
Vol 69 (8) ◽  
pp. 2075-2084 ◽  
Author(s):  
Tim P. Birt ◽  
John M. Green ◽  
William S. Davidson
Keyword(s):  
Atlantic Salmon ◽  
Atpase Activity ◽  
Growth Performance ◽  
Salmo Salar ◽  
Salinity Tolerance ◽  
Condition Factor ◽  
Chloride Cells ◽  
Group Differences ◽  
Atlantic Salmon Salmo Salar ◽  
Breeding Populations

Parameters associated with the parr–smolt transformation were compared in cultured 1+ anadromous and nonanadromous Atlantic salmon derived from wild broodstock collected in Gambo River, Newfoundland. Progeny of nonanadromous salmon were significantly longer at swim-up than progeny of anadromous salmon, although consistent differences in growth performance were not observed during most of the 1 st year of development. Anadromous salmon grew more rapidly than nonanadromous salmon in the spring months during the smolting period. Distinct differences were noted between groups in seasonal levels of body silvering, gill Na+–K+ ATPase activity, and size and number of gill chloride cells. Most male nonanadromous salmon matured as "post-smolts," whereas maturation was not observed among female nonanadromous nor among either sex in the anadromous group. Differences between anadromous and nonanadromous salmon were not observed in seasonal levels of body moisture, plasma Na+ and Cl−, condition factor, or salinity tolerance. Differences noted between groups are probably genetic in nature and suggest that the two forms of salmon in Gambo River represent separate breeding populations.

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